Introduction: Vitamin D deficiency is one of the most important medical problems, especially in children.. Vitamin D deficiency is associated with decreased insulin secretion, insulin resistance and type 2 diabetes. The purpose of this study is to investigate the relationship between vitamin D and insulin levels in obese children referred to Zahedan Aliasghar Hospital Materials and methods: In this study included 100 obese children referred to Ali Asghar Clinic in Zahedan, which They were investigated in 1402. The samples analyzed for insulin level and vitamin d level .The data was collected using observation and examination and experiments. Data analysis was done in SPSS version 24 software using independent T and Chi-square statistical tests. A significance level of less than 0.05 was considered. Results: In this study, there was 45% vitamin D deficiency, which was more common in obese boys (27 male ,18 female ) and vitamin D insufficiency was 44% which was more common in female. Vitamin D deficiency was more prevalent in obese children over the age of 10 .This study showed that obese children with vitamin D deficiency have higher insulin levels and insulin resistance. Discussion and conclusion: This study showed that obese children and adolescents are more at risk of vitamin D deficiency, Vitamin D deficiency is associated with increased inflammatory markers. In addition, genetic polymorphisms of vitamin D-related genes may predispose to dysglycemia and type 2 diabetes.